Rare bleeding disorder hemophilia A affects the blood’s ability to clot. The F8 gene, which is located on the X chromosome, is mutated, causing hemophilia A. The factor VIII protein is necessary for blood clotting, but is lacking in people with hemophilia A. It is possible for hemophilia A to cause excessive or spontaneous bleeding, especially in the joints, muscles, and internal organs. Infections, joint damage, and other complications are also common complications.
X-linked recessive hemophilia A is an inherited condition, meaning it is passed down from parents to children. Hemophilia A mostly affects men and people assigned male at birth (AMAB), as it is an inherited condition. There are also cases of hemophilia A in females and in people assigned female at birth (AFAB), but they are usually carriers who do not show symptoms. However, some women and AFAB people may experience mild bleeding problems if their factor VIII levels are low.
An individual with hemophilia A has a mutation in the F8 gene, which produces factor VIII. This mutation reduces or eliminates the production of factor VIII, resulting in impaired blood clotting. It may be inherited from one or both parents, or it may occur spontaneously.
As a result of hemophilia A, patients' symptoms vary according to the severity of the condition and their level of factor VIII. It is possible for people with severe hemophilia A to experience frequent and spontaneous bleeding, even without trauma or injury, despite having less than 1% of normal factor VIII levels. In people with moderate hemophilia A, factor VIII levels range from 1% to 5% below normal, and they may experience occasional bleeding, especially after surgery, dental work, or an injury. Those with mild hemophilia A may only experience bleeding after severe trauma or surgery because their factor VIII levels are 5% to 40% of normal.
The most common symptoms of hemophilia A are:
Bleeding into the joints, causing pain, swelling, stiffness, and reduced mobility. The knees, elbows, ankles, and hips are the most affected joints.
Bleeding into the muscles, causing bruising, swelling, and pain. The arms, legs, and abdomen are the most affected muscles.
Bleeding into the skin, causing large and deep bruises, especially after minor bumps or scratches.
Bleeding into the mouth, nose, gums, or throat, causing nosebleeds, bleeding gums, or difficulty swallowing.
Bleeding into the brain, causing headaches, nausea, vomiting, confusion, seizures, or loss of consciousness. This is a life-threatening emergency that requires immediate medical attention.
Bleeding into the urinary or digestive tract, causing blood in the urine or stool, abdominal pain, or vomiting blood.
Bleeding into the eyes, causing vision problems, pain, or redness.
When hemophilia A is diagnosed, factors VIII and clotting time are measured. A complete blood count (CBC) is a blood test that measures how many red blood cells, white blood cells, and platelets are present in the blood. A low number of red blood cells or platelets can indicate bleeding problems. A blood test called an activated partial thromboplastin time (APTT) can measure the time it takes for the blood to clot. A prolonged APTT can indicate a deficiency of factor VIII or other clotting factors. A blood test called a factor VIII assay can measure the amount of factor VIII in the blood. Low levels of factor VIII confirm hemophilia A diagnosis.
During pregnancy, the F8 gene mutation can also be detected for hemophilia A by testing fetal DNA or amniotic fluid. Invasive procedures such as chorionic villus sampling (CVS) and amniocentesis are used to do this. The umbilical cord blood or newborn's blood can also be tested for factor VIII levels to diagnose hemophilia A after birth.
Replacement therapy, which involves injecting factor VIII into the bloodstream to replace the missing or deficient protein, is the main treatment for hemophilia A. It is possible to give replacement therapy on demand, which means when bleeding occurs, or prophylactically, which means it is given regularly to prevent bleeding. Replacement therapy doses and frequencies are determined by the severity of hemophilia A, the type and location of bleeding, and the weight and age of the patient. Hemophilia replacement therapy can be administered at home, in a treatment center, or in a hospital.
In addition to plasma-derived factor VIII, recombinant DNA technology can also be used as a replacement therapy. Plasma-derived factor VIII is produced from donated blood that is screened for viruses and other contaminants. Genetically engineered cells produce factor VIII in a laboratory. Compared to plasma-derived factor VIII, recombinant factor VIII is considered safer and more effective, but it can also be more expensive and harder to obtain.
It is possible for some people with hemophilia A to develop inhibitors, antibodies that attack and destroy factor VIII, preventing replacement therapy from working. Inhibitors can be detected by a blood test called a Bethesda assay, which measures how much factor VIII is neutralized by the inhibitors. The treatment options for people with inhibitors may include higher doses of factor VIII, bypassing agents, immune tolerance induction, or gene therapy. Bypassing agents are clotting factors that activate the clotting process by bypassing factor VIII. In order to train the immune system to stop producing inhibitors, factor VIII is given at high doses over a period of time as part of immune tolerance induction. Using gene therapy, a normal copy of the F8 gene is inserted into the cells in order to restore factor VIII production.
Other treatments for hemophilia A include:
Antifibrinolytic drugs, such as aminocaproic acid or tranexamic acid, which can prevent the breakdown of blood clots and reduce bleeding.
Fibrin sealants, such as aprotinin, which can promote clotting and seal wounds.
Hormone therapy, such as desmopressin, which can stimulate the release of stored factor VIII from the blood vessels and increase the clotting ability. This treatment is only effective for people with mild hemophilia A or some carriers.
Blood transfusion, which can provide red blood cells, platelets, or plasma to replace the lost blood and improve the oxygen delivery and clotting function.
Physical therapy, which can help relieve pain, swelling, and stiffness in the joints and muscles, and improve the range of motion and strength.
Pain relievers, such as acetaminophen or ibuprofen, which can reduce pain and inflammation. However, some pain relievers, such as aspirin or naproxen, should be avoided because they can interfere with blood clotting and increase bleeding.
Hemophilia A cannot be prevented, but it can be managed with proper treatment and care. Some preventive measures that can help reduce the risk of bleeding and complications include:
Getting regular check-ups and blood tests to monitor the factor VIII levels and the bleeding status.
Following the prescribed treatment plan and keeping a record of the factor VIII doses, the bleeding episodes, and the response to treatment.
Avoiding activities that can cause injury or trauma, such as contact sports, sharp objects, or dental procedures, or using protective gear and equipment when necessary.
Applying pressure and ice to the bleeding site and elevating the affected limb to stop or slow down the bleeding.
Seeking medical attention immediately if bleeding is severe, persistent, or occurs in vital organs, such as the brain, lungs, or heart.
Avoiding medications that can affect blood clotting, such as aspirin, naproxen, warfarin, or heparin, unless prescribed by a doctor.
Practicing good hygiene and dental care to prevent infections and gum bleeding.
Eating a balanced diet and drinking plenty of fluids to maintain a healthy weight and hydration status.
Exercising regularly and gently to improve the blood circulation and the joint and muscle health.
Joining a support group or a counseling service to cope with the emotional and social challenges of living with hemophilia A.
Hemophilia A is a serious but manageable condition that requires lifelong treatment and care. With proper diagnosis, treatment, and prevention, people with hemophilia A can lead normal and productive lives.
